1. Field of the Invention
This invention relates generally to new methods and devices for placing stitches in relatively thick, moving tissue so that when the ends of the suture are drawn tightly together, the tissue within the suture is constricted and more particularly to methods and devices for the minimally invasive remote simultaneous and hemostatic placement of multiple horizontal mattress sutures centered circumferentially around a placed guide wire traversing through a tissue wound site that will subsequently be enlarged (to provide a passageway to facilitate a medical intervention) and then hermetically closed. An embodiment of the invention includes a hand actuated suturing instrument with multiple needles that drive through relatively thick engaged tissue each picking up an end of a strand of suture for the precisely oriented suture placement at predetermined depths of multiple concentric horizontal mattress sutures with pre-loaded pledgets. To enable accurate device placement on a potentially moving tissue structures, such as a beating heart, this suturing instrument incorporates a novel low profile pivoting or rotating mechanical alignment guide to enable controlled positioning of the distal end of the instrument at the desired location identified by a temporary guide wire traversing and centered on the pending access site. In accordance with another embodiment, to maintain reliable purchase (i.e., engagement) on such thick, moving tissue structures, this invention provides an additional mechanical means to accurately and securely engage the suturing instrument's suture placement distal end with the targeted tissue site. Examples illustrating novel methods of the use of this invention for the safe and secure closure of transapical heart access wounds and ascending aorta cannulation sites are also herein described.
2. Description of Related Art
Wounds in living tissues and organs are often created by physicians to provide a passageway or access to more internal structures for diagnostic and therapeutic interventions. Access wounds made in tissue structures that are thicker walled, not fixed in position (e.g., mobile or actively moving) or acting as barriers to hold pressurized fluids or gases can be more challenging to establish and close. Temporary guide wires are routinely positioned at proposed entry wound sites to provide a central target and guiding element for improved device placement accuracy during tissue access. For example, for access to the inside of the beating human heart, transmyocardial cannulation of the lateral left ventricle near the apex permits accessibility through the ventricular chamber to the region of the aortic root, the mitral valve and the left atrium. Another cardiac intervention example is the cannulation of the anterior ascending aorta to provide a site for antegrade passage of oxygenated blood during cardiopulmonary bypass. Guide wires can be installed to better enable transapical access to the moving, contracting left ventricle along with transmural access to the pulsatile ascending aorta. While a number of techniques and technologies already exist for closing various types of wounds, the need still exists for improved means for closing many tissue wounds created for advanced minimally invasive interventions. This need is critical for closing wounds accessed remotely through small openings, and especially, for securing wound closures of relatively thick tissues containing pressurized fluids, such as circulating arterial blood.
While this invention can be used for securing a wide variety of tissue structures, it is particularly useful for thicker, non-fixed tissue, as is often encountered in cardiac interventions. Since the invention has multiple potential cardiac applications, abridged heart anatomy highlights are presented next. The healthy human heart has four chambers: the right atrium, right ventricle, left atrium and left ventricle. This critical circulatory system organ is generally considered to have a “right” side, in which the right atrium receives from the body deoxygenated blood that the right ventricle pumps to the lungs and a “left” side, in which the left atrium receives from the lungs oxygenated blood that the left ventricle pumps into the systemic circulation. To maintain normal unidirectional blood flow and physiologic pressures, hearts have four valves: the right atrio-ventricular tricuspid valve, the pulmonary valve between the right ventricle and the pulmonary artery, the left atrio-ventricular mitral valve and the aortic valve between the left ventricle from the ascending aorta.
Over the past decade, a growing appreciation has developed for the potential to surgically intervene on the inside of the beating heart through small access wounds made directly through the muscular myocardial wall, typically near the pointed tip or apex of the anterior left ventricle. This so-called, Transapical Access approach has been proposed for interventions ranging from atrial endocardial ablations to mitral valve repairs to transcatheter aortic valve replacements. Transapical aortic heart valve replacement procedures are now in clinical use in Europe and North America.
A brief review of transapical endocardial ablations and mitral valve repairs include, for example, Lattouf (Pub. No: US2007/0270793 A1) proposed accessing the interior chamber of the left atrium via a penetrating access wound in the left ventricular apex wall, then retrograde through the chamber of the left ventricle and the mitral valve. After accessing the chamber of the left atrium and destroying the aberrant endocardial tissue, the apical closure was left to be performed by open traditional surgical techniques requiring a painful highly invasive thoracotomy incision in the chest wall. Lattouf also teaches (U.S. Pat. No. 6,978,176 B2) a method and devices for repair of the mitral valve's chordal attachments anchored within the left ventricle; they propose using a plastic plug for cannulation of the apical access wound, anchoring the new mitral chordal repair filaments and closing the apical wound. Gammie (U.S. Pat. No. 7,635,386 B1) showed a similar transapical approach to mitral valve repair with a different suturing device.
Transcatheter transapical aortic valve replacement is an area of concentrated research and significant clinical excitement at this time. At the May, 2010 American Association of Thoracic Surgeons, over twenty different presentations were offered on this subject; none offered minimally invasive or single port access or percutaneous technology for a least invasive route for transapical interventions. Reviews of the published literature on this subject demonstrate that no means currently exists clinically or proposed in research that has been publically offered for the minimally invasive closure of a transapical access site. Transcatheter transapical aortic valve replacement is currently reserved for the sickest cardiac patients, who are usually quite elderly, with multiple other co-morbidities and dying from otherwise inoperable critical aortic stenosis disease. A true minimally invasive access option would offer these highly compromised patients their best chance for a safe recovery.
While transcatheter transapical heart valve replacement products are already helping many patients, especially in Europe, until now an excellent means to remotely close transapical access wounds has remained elusive. Edwards® Lifesciences® provides the 31 Fr. Ascendra® transapical delivery system for 23 and 26 mm stainless steel bovine pericardium balloon expandable aortic valve xenografts; their full product launch is expected around 2012. In Europe, Medtronic® sells its Core Valve® re-valving system which incorporates a porcine aortic valve on an hourglass shaped nitinol frame, which is self expanding at body temperature. Medtronic's® Embracer® transapical delivery system products along with its Ventor® transfemoral versions are expected to be both released in 2014. The Medtronic® delivery system is 18Fr. and delivers valves that ultimately expand out to 20 and 27 mm. Medtronic® Melody® transcatheter pulmonary valve was first available in the United States in 2010. Other international companies, such as St. Jude Medical®, are reporting the development of transcatheter transapical valve products. To our knowledge, despite the clear need acknowledged for over the past half-decade, no one has yet reported an automated technology to facilitate truly minimally invasive transapical access site wound closure.
Many critically ill cardiac patients need their heart valves replaced, but no one would prefer a significantly large chest wall wound if a less traumatic, safe and effective alternative were clinically available. The first patient transcatheter aortic valve replacement occurred in France in 2002. Now, an estimated 50 transapical aortic valve replacement procedures occur each week throughout the world; all of these critically ill patients have required open chest surgery predominantly through the anterior lateral 6th costal interspace. This open technique is to expose the front of (i.e., the anterior surface of) the beating heart to enable traditional hand suturing techniques for preparation of the heart transapical access site. Hybrid operating rooms offer the convergence of interventional cardiology techniques with the effectiveness of heart valve replacement, which until recently required the direct application of the skilled hands of a cardiac surgeon. This modern collaboration will remain limited until a safe and reliable technology and techniques for truly minimally cardiac transapical interventions are available.
Over the past 5 decades, millions of patients have benefitted from cardio-pulmonary bypass to enable extracorporeal oxygenation and pressurization of blood reintroduced back into the open-heart surgery patients circulation during arresting of the heart. A common technique to provide a conduit for returning oxygenated blood back into cardio-pulmonary bypass patient's systemic circulation involves cannulating the patient's ascending aorta with a tube carrying pressurized oxygenated blood to provide access to the systemic circulation above the cross clamped aortic root. A better, less invasive means is needed for installing perfusion cannula tubes and subsequently closing an aortic cannulation site wound.
Many minimally invasive cardiac surgical procedures still require an arrested heart to ensure an effective intervention and enable required visualization. The patient can benefit enormously from the much smaller chest wound utilized for a minimally invasive mitral valve repair and still receive a long-term therapeutic effectiveness. Hand sewing a traditional double purse string suture into the ascending aorta through a minimally invasive small remote port site using standard needle drivers is so challenging that for most surgeons it would not be worth the additional risks. To avoid the direct transmural cannulation of the ascending aorta minimally invasive heart surgery, several suboptimal products are available. For example, Edwards® Lifesciences® offers a long balloon catheter, called EndoDirect®. This product can be threaded retrograde through the pulsating femoral artery in the groin up beyond the arch of the aorta, where its balloon is infused to occlude the most proximal aorta and permit infusion of pressurized, oxygenated blood into systemic circulation during iatrogenic cardiac arrest. These balloons tend to migrate to less appropriate locations and frequently require repositioning. Any catheter traversing the arch of the aorta risks displacing embolic material and inducing stroke and other complications. The large transmural wound in the femoral artery typically requires open surgery for arteriotomy repair. A minimally invasively delivered device to secure an aortic cannula during cardio-pulmonary bypass and to subsequently hermetically close the transmural access wound site would be a significant advance.
With the Minimally Invasive Surgery (MIS) revolution, several available suture placement products have offered surgeons working through small access sites alternatives to hand suturing and hand knot tying. The use of non-specialized laparoscopic or thoracoscopic needle drivers presents significant limitations to ergonomic and accurate remote suture placement. MIS suturing devices, such as the LSI SOLUTIONS® SEW-RIGHT® SR●5® (U.S. Pat. No. 5,431,666) and Running Device® (U.S. Pat. No. 7,407,505 B2) along with their TK-5® Ti-Knot® technology, Covidien's® Endostitch and Boston Scientific's® Capio®, provide shafted instruments for placing suture remotely. None of these products readily permits the accurate and simultaneous placement of concentric sutures at the tissue locations required in the applications.
Another related category of remote suturing instruments are usually called trocar wound closure devices, which are typically used to close the access site wound at trocar cannulation sites in the anterior abdominal wall. Typically these devices are suture mediated and their device distal ends enter the hole they are intended to close, which may be problematic in the above mentioned examples. These types of devices also typically close holes that are not associated with pressurized fluids, like blood. While many variations of trocar wound closure devices have come into use over the past two decades (U.S. Pat. Nos. 5,368,611 and 5,620,456), none are known to enable this transapical wound or aortic cannulation site preparation and closure.
Arteriotomy wound closure devices are another group of products that can be used to close some vascular wounds (e.g., a femoral artery percutaneous access site in the groin). Several suture mediated devices have been described to offer puncture wound closure options; U.S. Pat. Nos. 5,766,183; 6,368,334 B1; 6,641,592 B1 cover such technology. Alternatively, metal clips opposing wound edges U.S. Pat. No. 4,929,240 and absorbable plugs U.S. Pat. Nos. 4,852,568 and 5,342,393 were developed. Since these devices have also been available for some time, they appear unacceptable for the proposed related applications, including transapical access and aortic cannulation site closure.
A previous invention (Medical Instrument To Place A Pursestring Suture, Open A Hole And Pass A Guidewire, U.S. Pat. No. 7,731,727 B2) is somewhat similar in appearance to the current invention but has many distinct differences. The previous technology is remotely applied to thin walled tissue, which is sucked into place by vacuum for needle deployment using an integrated vacuum chamber; this tissue, such as stomach or rectal wall, needs to be highly conformal to avail itself to vacuum mediated deformation. Thicker walled structures may not be held reliably enough by vacuum alone. This previous instrument is not intended for use on tissue which is acting as a barrier to hold back pressurized fluids. The needles generally penetrate the full thickness of the tissue, which could cause immediate leakage of the pressurized fluid. Also the use of integrated cutting blade could cause an immediate hemorrhage, for example, in a beating heart. In addition, with this vacuum mediated technology, the guide wire is through the instrument at the end of the procedure after the purse string suture is placed and the transmural incision has been made; this is opposite of the current invention which traverses a pre-placed guide wire. In accordance with the present new invention for use with thicker tissue, the device end is inserted onto and follows an already existing temporary guide wire, which was previously installed to serve as a guide to the targeted tissue site. The previous technology does not teach a mechanical instrument-to-tissue alignment mechanism or an instrument-to-tissue secure engagement means based on compression between external and internal anchors. The previous technology was not intended for use with thick walled moving structures.
Despite a long recognized critical clinical need, no technology is known to exist that provides for the safe and effective minimally invasive closure of certain access wounds required for many therapeutic interventions, especially several related to cardiac procedures involving thicker tissue. This innovation now offers a new potentially highly effective and safe option for future patients.